Description: The objective of this Facility Core is to provide both routine histological processing, as well as more specialized histochemical and immunohistochemical techniques to Center Investigators. This Core also provides technical assistance, training, and consultations in histological techniques, necropsies and histopathological interpretation for Center Investigators. The objective of this Facility Core will be accomplished through the pursuit of four specific aims. They are: 1) to provide histology processing, including paraffin embedding, staining, frozen sections, and other conventional histology techniques; 2) to provide training and advice for morphology techniques to Center Investigators; 3) to develop new immunohistochemical or in situ hybridization approaches as required by Center Investigators; and 4) to serve as a consultant for the histopathological diagnosis of lesions produced in animal experiments.